Protein misfolding neurodegenerative diseases are placing an increasing burden on society due to the aging population and lack of adequate treatment options. For example, Huntington's disease affects about 30,000 people in the United States, and has a slowly progressive course where patients can live with the condition for 10-20 years before death occurs. Huntington's disease is caused by a CAG repeat expansion within the huntingtin gene which results in a polyglutamine repeat expansion in huntingtin protein (htt). The mutant huntingtin protein (mhtt) misfolds and accumulates primarily in brain neurons where it mediates toxic effects resulting in neuronal dysfunction and loss, which ultimately results in loss of brain functions and disease manifestations such as involuntary movements, lack of coordination, loss of balance, memory loss, and dementia. Decreasing the level of mutant huntingin protein in the brain is predicted to be of therapeutic benefit in Huntington's disease; however, this has not been achieved in human Huntington's disease patients.